Geezus, I feel like this car gonna b the death of me.

Have an '85 Z28 TPI/305 fresh rebuild. Spent bucket load of dinero on this stock rebuild. VERY few items didnt get replaced (with either new or in much better condition) then what was on orig. engine.

First let me say, this forum has been an invaluable resource to me over the past year as I've journeyed thru this rebuild process.

I've referenced & cross-referenced & triple-referenced & quadruple-referenced any issue thats ever surfaced during my rebuild of this engine (before moving any further along) by faithfully returning to this board and following (to the best of my ability) the instructions left by others who possess a far greater knowledge then I do. Believe me, I've logged MUCHO hours on here. I've tried to follow everything to the letter.

This is my situation.

Engine is now rebuilt and installed in the vehicle. Ignition timing has been set with timing light.

When I crank the car, this engine sounds beautiful. I mean, it literally purrs man.

I take it out of Park to put it in Drive for its initial "break in".

I begin to accelerate. It hesitates and then acts like the initial throttle pressure that I'm applying is trying its best to just choke the living life out of it. But, it does recover, and will begin to stumble forward.

This is the part that kills me str8 to the d%&ned heart, tho..

While all this is going on, I've got quite noticeable "blue smoke" coming out the exhaust. Ugh!!!!

Here is an exact description of what is happening with this vehicle:

-I crank it, it purrs. Couldn't ask for or expect a smoother sounding engine.

-At initial startup, no smoke. None at all. Not even the slightest puff.
It runs like that (super-clean) for several minutes, seemingly, without a hitch.

-Then, after it begins to warmup a little bit, I will begin to notice "blue smoke"...even as the vehicle is still sitting in Park and just idling. The amount of smoke is not constant...sometimes more sometimes less...doesn't seem to be smoking the same amount consistently.

I try to attempt to drive it down the street (a block or so). Car hesitates upon acceleration, stumbles, chokes down...even seems to stall in gear a little bit...but, runs real rough. I immediately turn around and bring it back into the driveway. Park it and turn it off.

I've closely monitored the coolant level for a possible head gasket leak. Have not noticed any measurable loss of coolant.

The engine does not leak any fluids (while running or otherwise) onto the road/driveway or onto the engine block itself.

The car has the proper amount of fluids in it (oil, tranny fluid, coolant, all new filters..also including a new fuel filter).

Dropped the tranny pan...saw no oil/water present. Resealed with new filter/gasket/fluid.

Drained oil, saw no water present. Refilled engine with new 30w dino oil.

Pulled plugs. Most were fouled with carbon build up. I understand this is typical. Cleaned all plugs and reinstalled. (Btw, all new distributor, points and plugs).

Have set and reset valve lash. I've tinkered with those valves/pushrods (both ways..engine running and off) to try to get them as precise as possible. If I've done those valves once...I've started over and done them at least 4 times (using both Kyles methods and Snakeskinners).

New gaskets on both V/C's. New Pcv valve.

I've gone through the timing process so many times that I think I could wake up in the middle of the night out of a dead sleep and recite all the necessary steps to complete the proper procedure for timing (to include a full description of what happens during the cranks rotation on a piston/cylinder vs pushrod/rocker arm as that piston is nearing its firing position).

I've already replaced the head gasket once. I've checked and triple checked for proper placement of plug wires. 1-8-4-3-6-5-7-2. I've repeatedly looked for any possible vacum leaks. Yesterday, I even got back under the car and double checked for any problems with exhaust connections (manifold to block/manifold to 'Y' pipe).

I've checked to make sure that the valleys in the heads are not obsructed and preventing proper oil flow/drainage. With engine running and valve covers off, all the pushrods are spurting oil and I notice none being either bent or broken.

The only other thing that I can think is that the speed shop that I paid to install the crank/connecting rods/ and pistons into the block...as well as, the heads that I paid them to rebuild (that I now have mounted....somehow goofed.

The thing is..this speed shop thats in my town here...well, they been in business here for years and years and years. They been here forever and even do alot of work on the racing engines for the guys that run in our stock car races and out on the 1/4 mile track in the next community over. I'm just sooo hesitant to think that it might be sumthing that they messed up on.

Is there a way that I can further investigate what might be the cause of the problems that I'm having with this engine without having to do a complete tear down on this block and all this work...again?

Any ideas from any thirdgen sages out there will be extremely welcome.

Please help.

Thanks.

 

blue smoke is because the piston rings havent seated. and the other sound like all timing. check you timing chain and make sure that is right because you may think it's in the right place but it could be a tooth off internally. check your points gap too. and you never know i would try the old distibutor if you had no problems with it before becuase the new one may be defective. good luck man.

 

Are you sure it's blue smoke? Any chance it's more black than blue? How does the exhaust smell? Is it running real rich?

It could be a stuck EGR, bad O2 sensor, or the seating rings. If this isn't a roller cam engine, did you do the 20 minutes at 2500 RPM cam break-in when you first started it?

 

I'll keep playin with the timing and see if that won't alleviate the "stumbling" that its been doing.

I did check the point gap on the plugs. I believe the recommended setting for them was at .045 (if i remember correctly).

The "new distributor" is the old one torn down and rebuilt. I replaced the capacitor, ignition module, rotor button, pick-up coil assembly, and the coil in the cap, as well as the cap itself.

I also removed the "pin" from the end of the dizzy, and took that "gear" piece off. I literally pulled everything apart , cleaned it, relubricated it, and then re-assembled.

But, I'm sure that it's blue smoke. Heh.

I was so hoping that blue smoke meant fuel, as it was a real let down when I learned otherwise.

I have gone thru the first part of the process of the warm-up procedure as outlined by the GM manual.

I found that info in a pdf attachment by another member of ThirdGen in a related article. Cuz, yeah...I'm thinking too that the seating is taking place (or should be) at @1800rpms ...so, I'm just so blown away when I started to see this smoke...still.
But, I did idle it at the 2k to 2500 RPM range like is outlined. Actually, I"ve done it a couple times already.

Perhaps it is cam timing. But, I do distinctly remember setting the points "dot to dot". I know when I set them that way, that I was at #6TDC.

But, I thought I remedied that difference (later)..when fiddling with timing.... by hand turning the crank and physically verifying TDC (compression) through the #1 spark plug hole in the front D/S of the block.

I'll redo the timing again and hopefully that will help. Maybe its just being real fickle til I hit the "sweet spot". Thanks for ya'lls input. :hail:

 

Just a long shot on the blue smoke out of your new rebuild...

I see that you're not running synthetic oil (at least not yet), and that's good. That could easily be keeping the rings from seating in from what I understand. Most rebuilders say to wait until you get 3000 - 5000 miles on a new engine before you shift over to synthetic. But that's not your problem since you said you're running dino oil.

I'm stumped. I just hope you don't have a ring problem (broken ring, wrong size rings or ring gap, or ring gaps lined up) or a head problem (bent or burned valve, bad valve seal, head gasket, etc.). Have you run a compression check on each cylinder yet? That would probably be my next step. Do it with the engine cold first. Since you see the smoke once it gets good and warmed up, you probably need to warm it up and check one cylinder, warm it up again and check the next cylinder, etc.

Maybe that will shed some light on things for us. Good Luck!!


- Vern

 

your not using platnum plugs are you. i had the same problem after my rebuild, but i raised the compression i threw the bosch platnums away and put in ac delco plugs and it cured all my problems.

 

No. I think they are just the standard, recommended "garden variety" spark plugs. But, they are the type called for with this vehicle. I did check that. Actually, I'm on my 2nd set now.

I plan to do that compression test very soon here in the near future, cuz I just dont have the instrument onhand right now. I'm gonna have to go out and buy it.

But, in the meantime, I was just wondering if it is possible that if a lifter is not seated all the way down, could it allow oil to bypass and reach a cylinder below? If it could or did, would ring gap on the piston matter at all? I mean, if the oil makes it to the cylinder...are all bets off, then? will the engine then begin expelling smoke regardless?

With a new rebuild, should it smoke at all? Only on start-up? Until the valves/rings seat? Within the first 500 miles?

Is there any rule of thumb for customary "breakin-in" period on a new block regarding an acceptable period of oil smoke?

Just curious. Thanks.

I do hope that I'm correct in assuming that the light-bluish smoke I'm getting is, in fact, oil and not gas.

As of yet, I've pretty much just had the thing in Park with the engine idling. Thats when I first noticed the smoking, and its continuity after letting it warm for 20-30 minutes or so and doing the recommended RPM "break in" process.

I have attempted a couple of "short" trips (around the block)...but, I've only got like...(at the most) ....2 miles on this engine right now.

But, the thing is ...I've let it idle like that in Park for those lengths of time (prolly a handful of times so far) and the smoke has never really let up. I've even allowed the engine to completely cool after a 20-30 minute idle, before I cranked it again..and then "bam" same old smoke would be coming back just like before. At first I thought..ok...its just initial burn-off...

But after the 2nd or 3rd or even 4th time of doing this deal of an "idling cycle" and not noticing a decrease in the amount of smoke (or the absence of it altogether) then, I start to worry that sumthin might be wrong internally and I don't wanna cause what might be a slight fracture to turn into a massive break if u know what i mean.

Am I being too cautious with this thing?

 

has the motor been bored?

 

when i rebuilt the engine in my car and was having problems with drivability, it ended up being that the torque converter was broken. It was putting too much load on the engine (kinda like letting the clutch out too fast in a manual car) and the thing would stall. It idled fine in park though. Did you get your tranny and torque converter checked/rebuilt/replaced?

 

I believe it was bored .30 over.
Basically, when i first started this project, I went to the oldest speed shop here in town and told them what I wanted to do and the resources I had available.

Armed with that information, they then basically provided me with all the parts that I would need for that engine to be rebuilt. They did handle installing the crank/connecting rods/and pistons. They also gave me a pair of their newly rebuilt heads.

Aside from that, I've put everything else together tho.

I told them I wanted to stick with a stock 305 rebuild since that was what the car was originally designed for and what I was already (at least, a little) familiar with.

I'm a novice. I'll admit it..lol.

I figured as long as I stayed as close to the original spec's of my car as possible, then with absence of any deviation, I hoped I would encounter less (if any) new problems rather than installing a different/larger engine. Plus, I didnt' want to run into a situation where I would be installing new parts that didnt didn't fully agree with any existing parts/accessories still in/on the vehicle.

I hope that makes sense. I felt I was already assuming a massive undertaking, and I didn't wanna go TOO FAR over into the deep end of the pool...lol.

As far as the transmission, it is still relatively new. Well, its a newly rebuilt 700r4 that was working fine before I attempted this undertaking. I was really having no problems with it at all.

 

Well, the smoking has ceased (for the most part, anyway). I still notice a little puff sometimes when I like pull up to a redlight /stop sign and idle for a minute. I still have very little mileage on the engine. But, thats about it. It doesn't smoke now like it was doing before if I just leave it to idle in Park. The "choking" at acceleration seems to have disappeared as well.

I've also played around with the timing some more, and it's still just purring right along just like it always has.

I'm starting to think that 87camaro28310 was right when he suggested that it might be the "seating" and that timing might've still been a little off. The car seems to be running much better now.

You know, I gotta hand it to all you guyz. Definitely. :hail: :hail: :hail:

Because, when I first started this "part-time" project/hobby of a rebuild this past June, I honestly had no clue at all as to what was the difference between a pushrod and a rockerarm.

Up to that point, the absolute most "in-depth" motor work I'd ever undertaken was maybe changing a belt or a transmission/oil filter. Honestly.

Before I started this project (and even later, at different points during the process) I questioned myself (more then once..lol) whether I should've ever even attempted something like this.

But, I kept on (nevertheless) because I didnt want to give up and "throw away" whatever time I'd already invested and money I'd already spent only to end up (spending even MORE money) by hiring a "mechanic" to finish the job I'd already started.

I just kept telling myself that "...willingness, patience, and labor" would see me through. I did my best to try to fully understand each of the necessary steps and the best way to go about them. And, I would never go to the next step in the process if I had anything so much as a "lurking doubt" of a suspicion as to my correct execution of the step I was presently on or just finishing. Believe me, I did ALOT of the same steps 3-4 times over again until I was finally satisfied.

That, and a BUNCH of reading/researching on this forum board..lol.

I did have a couple of "Haynes" manuals...roflmao...that were good for all the pictures they had ...considering the number of pictures they do contain..lol.
Oh yeah, and the tolerances they list..those too.


But now, it seems to be finished (for the most part) and I seem to have successfully done it. I might add, much to the surprise of some of my extended family and friends..hahah. I think (to themselves) they thought I was gonna blow it..lol.

But, I NEVER COULD'VE DONE IT WITHOUT THIS BOARD. PERIOD. HANDS DOWN, I BELIEVE THAT TO BE THE GAWD'S HONEST TRUTH. SERIOUSLY.

Haynes manuals alone ARE NOT enough.

To partially quote a famous personality, "If anybody should ever find themselves on the down-side of advantage" in questioning whether or not they are capable of achieving their own ThirdGen pursuits and goals, DON"T EVER GIVE UP. There is a wealth of information on these boards and a TON of knowledge.

I, for one, when I first started this undertaking, had limited funds, basically no mechanical training, just my own mechanics socket set and various assorted personal hand tools, a couple of Haynes manuals, a strong desire to chase a dream, and a solid internet connection to this website.

Armed only with those few things, an absolute novice was able to read and learn how
to pull an existing engine out of a car, take it most of the way apart, put most of a brand new engine back together, and successfully re-install it and get it to run properly in his vehicle.

All of this I did alone but can only take VERY LITTLE credit. It would have been impossible for me without this board, and I'm EXTREMELY grateful to all of you. Even to those people that have posted and are now probably long since gone. Their posts were invaluable to me as well.

In saying all this, I now hope my engine doesn't blow up inside the car as I'm driving this afternoon...roflmao. But, I think the chances of that happening are pretty slim..lol.

I hope that maybe one day a moderator or moderators will see this post of mine. Cuz, in case any of them been wondering whether or not what they're doing here is worthwhile.....IT IS.

Cuz, ya'll having this forum here has given me more then just a new engine....it's given me a mechanical knowledge that will far outlast any engine parts I might have presently installed.

I salute all of you.

Respectfully,

pOOn

:hail: :hail: :hail:

 

just remember to keep an eye on you temp because my motor is bored .030 over too and they tend to run warm. good luck with it.